The Fact those 6 players on the other team stayed in that lobby is a absolute Miracle! That is 100% not the normal on MW3 at all. Reminds me of COD3 and COD4 lobbies like that. I haven't seen this since then.
Join off of a second account with really terrible stats (0 kills and a lot of deaths with as little score as possible). Let it join into a lobby then you join after the lobby is already formed and you will play against people who also have terrible stats.